Abstract：
Campylobacter jejuni continues to be a major public health issue worldwide. Poultry are recognized as the main reservoir for this foodborne pathogen. Implementing measures to decrease C. jejuni colonization on farms has been regarded as the most effective strategy to control the incidence of campylobacteriosis. The probiotics supplementation has been regarded as an attractive approach against C. jejuni in chickens. Here the inhibitory effects of one probiotic B. velezensis isolate CAU277 against C. jejuni was evaluated in vitro and in vivo. The in vitro antimicrobial activity showed that the supernatant of B. velezensis exhibited the most pronounced inhibitory effects on Campylobacter strains compared to other bacterial species. When co-cultured with B. velezensis, the growth of C. jejuni reduced significantly from 7.46 log10 CFU/mL (24 h) to 1.02 log10 CFU/mL (48 h). Further, the antimicrobial activity of B. velezensis against C. jejuni remained stable under a broad range of temperature, pH, and protease treatments. The in vivo experiments demonstrated that oral administration of B. velezensis significantly reduced the colonization of C. jejuni by 2.0 log10 CFU/g of feces in chicken cecum at 15 d postinoculation. In addition, the supplementary of B. velezensis significantly increased microbial species richness and diversity in chicken ileum, especially enhanced the bacterial population of Alistipes and Christensenellaceae, and decreased the existence of Lachnoclostridium. Our study presents that B. velezensis possesses antimicrobial activities against C. jejuni and promotes microbiota diversity in chicken intestines. These findings indicate a potential to develop an effective probiotic additive to control C. jejuni infection in chicken.
摘要：
空肠弯曲杆菌仍然是世界范围内的主要公共卫生问题。家禽被认为是这种食源性病原体的主要宿主。实施减少农场空肠弯曲杆菌定植的措施被认为是控制弯曲杆菌病发病率的最有效策略。益生菌补充被认为是针对鸡的空肠弯曲菌的有吸引力的方法。在此,在体外和体内评价了一种维氏芽孢杆菌(B.velezensis)益生菌分离物CAU277对空肠弯曲杆菌的抑制作用。体外抗微生物活性表明，与其他细菌相比，维氏芽孢杆菌的上清液对弯曲杆菌菌株表现出最明显的抑制作用。当与维氏芽孢杆菌共培养时，空肠弯曲杆菌的生长从7.46log10CFU/mL（24h）显着降低到1.02log10CFU/mL（48h）。Further,维氏芽孢杆菌对空肠杆菌的抗菌活性在很宽的温度范围内保持稳定，pH值,和蛋白酶处理。体内实验表明，在接种后15d，口服维氏芽孢杆菌可将空肠弯曲杆菌的定植显着降低2.0log10CFU/g粪便。此外,维氏芽孢杆菌的补充显着增加了鸡回肠中微生物物种的丰富度和多样性，特别是增强了Alistipes和Christensenellaceae的细菌种群，并减少了衣原体的存在。我们的研究表明，维氏芽孢杆菌具有抗空肠弯曲杆菌的抗菌活性，并促进鸡肠微生物群的多样性。这些发现表明开发有效的益生菌添加剂以控制鸡的空肠弯曲菌感染的潜力。
